The present invention relates generally to non-contact wiper and washer assemblies and, more particularly, to non-contact wiper and washer assemblies for surveillance camera domes.
Today, in the security industry, more and more emphasis is placed on discreet video surveillance by means of video cameras placed in housings having hemispherical transparent plastic domes. The camera is remotely rotated and pivoted within the dome so that the whole hemispherical viewing area may be surveyed.
It is extremely important that the camera have an unobstructed view of the viewing area at all times. This has not always been possible in the case of outdoor locations due to weather conditions, dust and other contamination that settle on the dome surface. Previously, there had been no easy method to remove water droplets from the surface of a plastic dome, nor to clean the surface of a dome other than manually cleaning it. The plastic material that the dome is made of is, by necessity, relatively soft and prone to nicks and scratches which will impair vision through the dome. Therefore, extreme care had to be exercised when cleaning the dome surface. This process has been necessarily time consuming and expensive and has often required premature replacement of the dome. Furthermore, cameras are frequently located at elevated or inaccessible locations requiring specialized equipment to gain access to them and making the process of cleaning the dome even more expensive.
The object of the invention is to provide a device which enables cleaning and wiping of a dome surface from a remote location without physically touching the surface.
It is also an object an advantage of this invention to reduce the cost of periodic maintenance of surveillance domes by providing a means for remotely cleaning the dome surface without the need for gaining physical access to dome.
It is a further object of this invention to provide a method for cleaning a dome exterior without touching its surface, thereby eliminating the possibility of scratching the surface.
It is a further object of this invention to avoid premature replacement of a plastic surveillance dome due to improper cleaning practices.
It is still another object of this invention to provide a device for wiping a dome surface clean of water droplets without physically touching its surface.
This invention provides a non-contact wiper and washer system for surveillance domes enabling an operator at a remote location to:
1. wipe the surface of the dome free of water droplets in rainy weather; and
2. wash and wipe the surface of the dome when contamination is present.
A semicircular thin walled tube is attached to the dome assembly, the tube being at all points in close proximity to the transparent dome surface. The tube has many small perforations placed so that compressed air or window washer solution may be dispensed at high pressure onto the dome surface. The semicircular tube is pivotable about an axis running through the center of the dome such that when pivoted 180 degrees, the whole surface of the dome may be cleaned. A remotely controlled electric motor is connected to the tube through a linkage transmission enabling it to move in the aforementioned manner.
In a preferred embodiment, the tube is connected to a pressurized supply tank containing window washer solution and air. The tank may be placed at a distance from the dome assembly. The connection to the tank is made by means of two supply lines, one from the top of the tank and the other from the bottom, enabling either air or washer solution to be dispensed. The connection is made through a xe2x80x9cTxe2x80x9d fitting and two electro-mechanical valves which may also be remotely controlled. The valves are controlled by logic circuitry to allow the operator to select either continuous wiper operation in case of wet or rainy weather conditions, or a wash cycle in the event the dome surface must be cleaned. The wash cycle may be automatically followed by a wipe cycle.
Pressurization of the supply tank may be accomplished by any convenient means such as an air compressor, compressed air bottle, hand pump or an existing compressed air line.